Bug correction in B05La_cah

A bug preventing correct use of chart$horizontal() and chart$vertical() is circumvented in learnr

Feedback form added (B99La_avis)

v2020.4.0

"Tutorial" B99La_avis to get feedback added

New tutorial B04La and several shinyapps

v2020.3.0

New version

B03La_mod_lin

minor changes in B03La_mod_lin

update B03La_mod_lin

v2020.2.3

update B03La_mod_lin

update B02La_mutli

B02La_mutli

Update tutorials B02La et B02Lb

tutorials version 2020

Update all tutorials with the new BioDataScience conventions

v2020.1.1

new version

Tutorials B01La_rappel & B01Lb_reglin1

Update tutorials B01La_rappel & B01Lb_reglin1 for better interaction with the gradethis package

Tutorial 06b and 06c

v2019.12.0

update package